EA experiment raises questions over incinerator emissions

Trials of new technology designed to sample dioxin emissions have suggested existing techniques may miss the whole picture.

Accurately monitoring harmful dioxin samples in an industrial setting is extremely difficult due to the tiny proportion they make up of the total emissions.

The Environment Agency has been testing experimental technology at the Eastcroft municipal waste incinerator in Nottingham and the Lafarge cement kiln at Cauldon in Staffordshire and published the results this month.

It found that at the incinerator some results from the continuous sampling appeared higher than results from the existing sampling which is required by the EU incineration directive.

The Environment Agency's director of environmental protection, Tricia Henton said: "This new technology could provide us with useful information about dioxin emissions in the future but these results are inconclusive, and we will be conducting further work to understand more about them and whether they are accurate or not.

"The levels of dioxins emitted by incinerators and cement kilns are so small they are very difficult to test for. We are talking about levels that are as less than one tenth of a thousandth of a millionth of a gram. As a result, the smallest change to the conditions of the test can have a huge impact on the findings.

"That's why more research and testing is needed. We have no reason to doubt the reliability of our existing sampling system, which is tried, tested and meets the European standard.

"People should have no cause for concern. You are exposed to more dioxins from bonfires and barbeques than from municipal waste incinerators.

"In 2004 the total amount of dioxins emitted by municipal waste incinerators in England and Wales was 2g, which accounts for less than 2 per cent of all dioxins emitted nationally."

Dioxins are widely encountered toxic substances and are particularly problematic due to their persistence in the environment.

Being fat soluble, they tend to accumulate in higher animals - including humans - and even very small dioxin concentrations can cause negative effects on the environment and human health, in particular on the most vulnerable groups like children.

Their resistance to degradation and semi-volatility means that they may be transported over long distances and give rise to trans-national exchanges of pollutants.

In addition, dioxins which were released into the environment many years ago are still contributing to current exposure.

Emissions from cement kilns and municipal waste incinerators are subject to strict European regulations and are very closely monitored and regulated by the Environment Agency.